gin框架路由讲解

点击关注👉 马哥Linux运维 2024-01-23 17:45 发表于江苏听全文

表单参数

表单参数传输为post请求，http常见的传输格式为四种

application/json
application/x-www-form-urlencoded
application/xml
multipart/form-data

表单参数可以通过PostForm()方法获取，该方法默认解析的是x-www-form-urlencoded或from-data格式的参数

<!DOCTYPE html><html lang="en"><head>    <meta charset="UTF-8">    <meta name="viewport" content="width=device-width, initial-scale=1.0">    <meta http-equiv="X-UA-Compatible" content="ie=edge">    <title>Document</title></head><body>    <form action="http://localhost:8080/form" method="post" action="application/x-www-form-urlencoded">        用户名：<input type="text" name="username" placeholder="请输入你的用户名">  <br>        密   码：<input type="password" name="userpassword" placeholder="请输入你的密码">  <br>        <input type="submit" value="提交">    </form></body></html>

package main
import (  "fmt"  "net/http"
  "github.com/gin-gonic/gin")
func main() {  r := gin.Default()  r.POST("/form", func(ctx *gin.Context) {    types := ctx.DefaultPostForm("type", "post")    username := ctx.PostForm("username")    password := ctx.PostForm("userpassword")    ctx.String(http.StatusOK, fmt.Sprintf("username:%s,password:%s,type:%s",      username, password, types))  })  r.Run()}

上传文件

multipart/form-data格式用于文件上传
gin文件上传与原生的net/http方法类似，不同在于gin把原生的request封装到c.Request中

<!DOCTYPE html><html lang="en"><head>    <meta charset="UTF-8">    <meta name="viewport" content="width=device-width, initial-scale=1.0">    <meta http-equiv="X-UA-Compatible" content="ie=edge">    <title>Document</title></head><body>    <form action="http://localhost:8080/upload" method="post" enctype="multipart/form-data">          上传文件:<input type="file" name="file" >          <input type="submit" value="提交">    </form></body></html>

package main
import (  "net/http"
  "github.com/gin-gonic/gin")
func main() {  r := gin.Default()  //限制上传最大尺寸  r.MaxMultipartMemory = 8 << 20  r.POST("/upload", func(ctx *gin.Context) {    file, err := ctx.FormFile("file")    if err != nil {      ctx.String(500, "上传图片出错")    }    //保存文件    ctx.SaveUploadedFile(file, file.Filename)    //返回输出消息    ctx.String(http.StatusOK, file.Filename)  })  r.Run()}

限制上传指定文件大小以及文件类型

package main
import (    "fmt"    "log"    "net/http"
    "github.com/gin-gonic/gin")
func main() {    r := gin.Default()    r.POST("/upload", func(c *gin.Context) {        _, headers, err := c.Request.FormFile("file")        if err != nil {            log.Printf("Error when try to get file: %v", err)        }        //headers.Size 获取文件大小        if headers.Size > 1024*1024*2 {            fmt.Println("文件太大了")            return        }        //headers.Header.Get("Content-Type")获取上传文件的类型        if headers.Header.Get("Content-Type") != "image/png" {            fmt.Println("只允许上传png图片")            return        }        c.SaveUploadedFile(headers, "./video/"+headers.Filename)        c.String(http.StatusOK, headers.Filename)    })    r.Run()}

上传多个文件

package main
import (   "github.com/gin-gonic/gin"   "net/http"   "fmt")
// gin的helloWorld
func main() {   // 1.创建路由   // 默认使用了2个中间件Logger(), Recovery()   r := gin.Default()   // 限制表单上传大小 8MB，默认为32MB   r.MaxMultipartMemory = 8 << 20   r.POST("/upload", func(c *gin.Context) {      form, err := c.MultipartForm()      if err != nil {         c.String(http.StatusBadRequest, fmt.Sprintf("get err %s", err.Error()))      }      // 获取所有图片      files := form.File["files"]      // 遍历所有图片      for _, file := range files {         // 逐个存         if err := c.SaveUploadedFile(file, file.Filename); err != nil {            c.String(http.StatusBadRequest, fmt.Sprintf("upload err %s", err.Error()))            return         }      }      c.String(200, fmt.Sprintf("upload ok %d files", len(files)))   })   //默认端口号是8080   r.Run(":8000")}

路由组

routes group是为了管理一些相同的URL

package main
import (  "fmt"
  "github.com/gin-gonic/gin")
func login(ctx *gin.Context) {  name := ctx.DefaultQuery("name", "yangchao")  ctx.String(200, fmt.Sprintf("hello %s\n", name))
}
func submit(ctx *gin.Context) {  name := ctx.DefaultQuery("name", "hcie")  ctx.String(200, fmt.Sprintf("hello %s\n", name))
}
func main() {  //创建路由  //默认使用了2个中间件Logger(),Recovery()  r := gin.Default()  //路由组1处理get请求  v1 := r.Group("/v1")  //{}是书写规范  {    v1.GET("/login", login)    v1.GET("/submit", submit)  }  v2 := r.Group("/v2")  {    v2.POST("/login", login)    v2.POST("/submit", submit)  }  r.Run()}

测试

实现404页面

package main
import (  "fmt"  "net/http"
  "github.com/gin-gonic/gin")
func main() {  r := gin.Default()  r.GET("/user", func(ctx *gin.Context) {    //指定默认值    name := ctx.DefaultQuery("name", "yangchao")    ctx.String(http.StatusOK, fmt.Sprintf("hello %s", name))  })  //指定404  r.NoRoute(func(ctx *gin.Context) {    ctx.String(http.StatusNotFound, "404 no found 1123131")  })  r.Run()
}